The immediate sequence here is what I'm having trouble with. They stashed the Yukon at the hayfield on the corner of Book Road and Trinity, a long block north of the Bosma house. However, Bullman (Day 5) says the truck and the Yukon pulling out of that field minutes later (about 5 minutes after they left Bosma house) and the two vehicles were captured on video northbound on Trinity Road approaching Wilson across from the Ancaster Fairgrounds, about 9:20 or so thus the evidence seems to be that they headed over to pick up the Yukon immediately after leaving the Bosma house, then went north on Trinity (though neighbour Bullman reportedly saw them going west on Book Road, which doesn't fit).
Hard to figure where and when the shooting took place. The video doesn't provide much wiggle room for a stop in the field, and I seriously doubt that the gun was fired in a public place. OTOH, did they manage to tell TB some story and persuade him to continue with the test drive up Trinity Road? They presumably turned west on Wilson, and there are some rather dark and lonely stretches of road between there and Brantford. Did a struggle perhaps ensue along there when TB realized this wasn't a regular test drive?